Don is quite correct.
With all due respect, the article seems quite out of touch with the playing card collector's market, and is only looking at some well known brands/names.
There are many far more rare decks, many of which you will rarely ever see on eBay given how much in demand they are. The fact that all these decks even have multiple copies for sale on eBay confirms that they aren't that rare.
Also, the article appears to confuse price with rarity. Price is largely driven by supply and demand, and not necessarily rarity. There are many far more rare decks that might not fetch figures as high as the original Fontaine decks, for example, which are largely driven by the "name brand" effect.